3ObjectivesConstruct a battery powered by a lemon. Observe and measure electrical voltage. Observe polarity(+, -) Analyze and discuss observations and data with other students. Relate findings to principles of electrochemistry.
11BATTERY BASICS The lemon juice allows the metal plates to gain or lose electrons. Then, those electrons travel over to theother plate. ( Zn lose e- / Cu gains e- )The reaction creates a different electrical potential onthe two different plates, so connecting them shows avoltage difference.e-
15Procedure APull the plunger all the way out. Put your finger on the end. Place the plunger back into the syringe and push the plunger in as hard as you can.It gets (easier, harder) to push the plunger in as you decrease the gas volume.
16Procedure BPush the plunger all the way in. Put your finger on the end. Attempt to remove the plunger from the syringe.Is it difficult to remove the plunger?
17QuestionsIn general, how do gas molecules create pressure upon their container? (What are the molecules doing?) In Procedure A, when you compressed the plunger, it got more and more difficult to push the plunger in. Explain why. (Discuss molecules and collisions) In Procedure B, you found that it was difficult to pull the plunger out. Why was it so difficult? (What force is responsible? Hint: vacuum is not a force)